GSF.IO.FileStructure.IndexParser.UpdateBlockInformation C# (CSharp) Method

        private void UpdateBlockInformation()
        {
            int lowestChange;
            if (m_oldFirstOffset != FirstIndirectOffset)
                lowestChange = 1;
            else if (m_oldSecondOffset != SecondIndirectOffset)
                lowestChange = 2;
            else if (m_oldThirdOffset != ThirdIndirectOffset)
                lowestChange = 3;
            else if (m_oldFourthOffset != FourthIndirectOffset)
                lowestChange = 4;
            else
            {
                lowestChange = 5;
                //DataClusterAddress = m_subFile.DirectBlock;
                return;
            }

            m_oldFirstOffset = FirstIndirectOffset;
            m_oldSecondOffset = SecondIndirectOffset;
            m_oldThirdOffset = ThirdIndirectOffset;
            m_oldFourthOffset = FourthIndirectOffset;

            if (FirstIndirectOffset != 0) //Quadruple Indirect
            {
                FirstIndirectBlockAddress = m_subFile.QuadrupleIndirectBlock;
                if (lowestChange <= 1)
                    SecondIndirectBlockAddress = GetBlockIndexValue(FirstIndirectBlockAddress, FirstIndirectOffset, BlockType.IndexIndirect1, FirstIndirectBaseIndex);
                if (lowestChange <= 2)
                    ThirdIndirectBlockAddress = GetBlockIndexValue(SecondIndirectBlockAddress, SecondIndirectOffset, BlockType.IndexIndirect2, SecondIndirectBaseIndex);
                if (lowestChange <= 3)
                    FourthIndirectBlockAddress = GetBlockIndexValue(ThirdIndirectBlockAddress, ThirdIndirectOffset, BlockType.IndexIndirect3, ThirdIndirectBaseIndex);
                if (lowestChange <= 4)
                    DataClusterAddress = GetBlockIndexValue(FourthIndirectBlockAddress, FourthIndirectOffset, BlockType.IndexIndirect4, FourthIndirectBaseIndex);
            }
            else if (SecondIndirectOffset != 0) //Triple Indirect
            {
                FirstIndirectBlockAddress = 0;
                SecondIndirectBlockAddress = m_subFile.TripleIndirectBlock;
                if (lowestChange <= 2)
                    ThirdIndirectBlockAddress = GetBlockIndexValue(SecondIndirectBlockAddress, SecondIndirectOffset, BlockType.IndexIndirect2, SecondIndirectBaseIndex);
                if (lowestChange <= 3)
                    FourthIndirectBlockAddress = GetBlockIndexValue(ThirdIndirectBlockAddress, ThirdIndirectOffset, BlockType.IndexIndirect3, ThirdIndirectBaseIndex);
                if (lowestChange <= 4)
                    DataClusterAddress = GetBlockIndexValue(FourthIndirectBlockAddress, FourthIndirectOffset, BlockType.IndexIndirect4, FourthIndirectBaseIndex);
            }
            else if (ThirdIndirectOffset != 0) //Double Indirect
            {
                FirstIndirectBlockAddress = 0;
                SecondIndirectBlockAddress = 0;
                ThirdIndirectBlockAddress = m_subFile.DoubleIndirectBlock;
                if (lowestChange <= 3)
                    FourthIndirectBlockAddress = GetBlockIndexValue(ThirdIndirectBlockAddress, ThirdIndirectOffset, BlockType.IndexIndirect3, ThirdIndirectBaseIndex);
                if (lowestChange <= 4)
                    DataClusterAddress = GetBlockIndexValue(FourthIndirectBlockAddress, FourthIndirectOffset, BlockType.IndexIndirect4, FourthIndirectBaseIndex);
            }
            else if (FourthIndirectOffset != 0) //Single Indirect
            {
                FirstIndirectBlockAddress = 0;
                SecondIndirectBlockAddress = 0;
                ThirdIndirectBlockAddress = 0;
                FourthIndirectBlockAddress = m_subFile.SingleIndirectBlock;
                if (lowestChange <= 4)
                    DataClusterAddress = GetBlockIndexValue(FourthIndirectBlockAddress, FourthIndirectOffset, BlockType.IndexIndirect4, FourthIndirectBaseIndex);
            }
            else //Immediate
            {
                FirstIndirectBlockAddress = 0;
                SecondIndirectBlockAddress = 0;
                ThirdIndirectBlockAddress = 0;
                FourthIndirectBlockAddress = 0;
                DataClusterAddress = m_subFile.DirectBlock;
            }
        }